Generally, a non-reciprocal circuit such as a circulator and isolator has characteristics of transferring a signal in the transmission direction almost without attenuation, and transferring a signal in the reverse direction with large attenuation, and is sometimes used for a transmitting/receiving circuit of communication equipment.
With downsizing of recent communication equipment, a smaller size non-reciprocal circuit is required.
For example, the following Patent Document 1 discloses a non-reciprocal circuit that has trifurcated microstrip lines formed on a magnetic material applied with a bias magnetic field by a permanent magnet.
Here, as for the input/output terminals for inputting or outputting a signal is drawn outside the outer surface of the permanent magnet.